Neighbor sum distinguishing total colorings of triangle free planar graphs

A total k-coloring c of a graph G is a proper total coloring c of G using colors of the set [k] = {1, 2, ..., k}. Let f(u) denote the sum of the color on a vertex u and colors on all the edges incident to u. A k-neighbor sum distinguishing total coloring of G is a total k-coloring of G such that for each edge uv . E(G), f(u) . f(v). By ..nsd(G), we denote the smallest value k in such a coloring of G. Pil.niak and Wo.niak conjectured that ..nsd(G) . .(G)+3 for any simple graph with maximum degree .(G). In this paper, by using the famous Combinatorial Nullstellensatz, we prove that the conjecture holds for any triangle free planar graph with maximum degree at least 7.